Automatic hydraulic power unit



July 28, 1959 s. s. SCHMIDT' AUTOMATIC HYDRAULIC POWER UNIT Filed March l. 1954 5 Sheets-Sheet 1 mow U mm W inf! @Nm mom o M r mm om om @om /7 Af //J A ATTORNEYS July 28, 1959 s. s. SCHMIDT AUTOMATIC HYDRAULIC POWER UNIT 5 Sheets-Sheet 2 Filedmarch 1. 1954 k 5255/5/55555/5/ os ggg e mmf ...GN oww @om Q mm mw N o `m N. @MW\ f ff /WVV/// TNI wNIN man Nm OO? O l1'. O. l l l I l a l e f n 1 f vl l A mm "wm mmm wm ATTORNEYS July 28, 1959 s. s. SCHMIDT AUTOMATIC HYDRAULIC POWER UNIT 5 Sheets-Sheet 3 Filed March l. 1954 INVENTOR.

FIGS.

ATTORNEYS July 2.8, 1959 s. s. SCHMIDT AUTOMATIC HYDRAULIC POWER UNIT 5 Sheets-Sheet 4 Filed March l. 1954 Fass,

July 28, 1959 s. s. sczHMlDTv AUTOMATIC HYDRAULIC POWER UNIT 5 Sheets-Sheet 5 Filed March l. 1954 HYD RAULIC SOLENOID HOLD R ELAY nvnRAuLlc VALVE STOP soLENom SWITCH START IR SOLENOID BUTTON Y HOLD RELAY RAPID ,APPROACH AIR STOP SWITCH ,SOLENOID VALV E FIGSA.

INV TOR.

ATTORNEYS Unite S ateS AUTOMATIC POWER Samuel S. Schmidt, Hazel Park, Mich. Application -March 1, 1954, Serial No. 413,170 10 Claims. (Cl. 60-952) delivery pump for operating and `controlling `the quill feed.

Still `another object is to provide novel means for adjusting pump delivery and quill feed.

`Other objects will readily appear to those skilled in the art upon reference tothe following description and the'accornpanying drawing in which Fig. l is a longitudinally vertical sectional View of the unit, the `plane being through the axis ofthe quill.

Fig. 2 is a similar' View, being an enlargement of a `portion of Fig. 1.

Fig. 3 is `an end elevation as from the left of Fig. l. Fig. 4 is a section on line 4 4 of Fig; l. Fig. `5 is a section on line 5 5 of Fig. 3. Fig. 6 is a section on line 6 6 of Fig. 3. Fig. 7 `is `a section online 7 7 of. Fig. l.. Fig. v8 is a section `on line 8 8 `of Fig. 9. Fig. 9 is a section on line 9 of Fig. -8. Fig. 10 isa wiring diagram showing the electrical control of theiunit.

Fig. `3A is a side elevation ofthe unit.

As indicated in the drawings, a unit embodying the present invention comprises a casing or housing 2d adapted to be completely filled with oil through a suitalble ller opening 29A, the moving `parts within the casing operating in the oil. One end of the casing 2i) "is closed bythe head 2GB in which is mounted the drive shaft 25 in the anti-friction bearing 24 and upon the outer `endet which isiixed a suitable drive pulley 25A, a suitable oil seal beingindieated at 24A.

The innerend of shaft 2.5 is` drilled axially as at 25B and provided with radial passages 25C opening into the axial passage near its `inner end, and to this end of the shaft `is aixed `a `cylindrical cylinder block 2d, to be described in detail later.

To the other end `of `.the cylinder block is ned a tube 27 extending to near the other end of housing T23 and `having xed to its end the drivenut 27A provided with 'a splined axial opening in 'which is spline'd the the tube 27 being provided with oil passage tudinally inward of the nut.

The inne-r end of the quiil 23, within tbe tube 27 is provided 'with a piston 3d, fitting `within tube 2? as a cylinder. The. piston consists of an annular tbody portion 36A held in place upon the reduced end of the quill by means of retainer 3dB, the retainer and adjacent end portion of the quiii being provided with an Vaxial passage 30C open Vto a diametrical passage 30D in the quill.I The axial passagellC is :provided with a valve seatfor the ball vvalve 30E adapted to `open toward the piston' head.

At its other end, the .quill 28 is `carried in suitable `antifriction bearings 3-1 in the end of a second and larger tube 32 arranged to'slide longitudinally in `a slide Vor guide 32A formed integral with the casing 2i), the end of the tube projecting from the casing and having fixed thereto a dial member 52B. The quill end, of course, projects from the Vtuhe 32 and is provided with means by which a tool may be attached. Between the dial member 32B and a suitable shoulder 33B on the exterior of tube 32 a plate 33 is rotatably fitted upon the tube. This plate is iixed to the piston rod 33A of an air cylinder 34, the use of which will-appear later.

Further, the tube 32 is threaded for a considerable portion of its length `from the inner end and carries thereon a traveling nut 32C suitable means (not shown) being 'provided to prevent nut rotation. By means of `the dial 32B, therefore, the location of the nut 32C may be adjusted so 4that outward travel of tube `32 may be limited or determined, lthe nut striking against a stop shoulder 32D `forming part of the housing.

As `indicated above, when shaft 25 is rotated, it carries with it the cylinder block 26 to which is `attached tube 27. This latter in `turn carries -the drive Anut 27A in which the quill 28 is splined. The cylinder block 26 is provided with an axial passage 26A `registering with the passage 25B in shaft 25 and also with a plurality of substantially axially arranged pump cylinders 26B (preferably three in number only one `being shown) the pistons 26C for which extend from the exposed end of the block and are r provided with universally mounted shoes 26D adapted to coact with the adjacent face of a wobble .plate 26E, suitable springs 26F tending to maintain shoe and plate Contact.

At the delivery end of each pump cylinder is a spring actuated jball valve 26H and adjacent thereto a ball inlet valve 261. -ln addition to the pumps, the block 26 is provided with a substantially axial ,passage 2.6K connected to a radial `outlet 26L and controlled by a check valve 26M.

As shown in Figs. l and 12, the swashplate 26E `is tiltably supported near its `lower edge upon stud 126, of which there `are `preferably two (only one being shown), and. capable of being tilted from` a position normal to the axis of the cylinder block (full lines) to a .position in which it is at a considerable angle (dotted lines).

`By suitably regulating the angle of the plate 26E, the length of stroke of the pistons 26C may be regulated and thereby the `delivery volume of oil from the pumps into the space between piston 3l) andthe end of -the cylinder block Z6.

Plate 26E near its upperedge is traversed by a stud 35 xed in the casing wall and provided with ya head 35A adapted to limit the movement of the plate beyond its position `normal te the cylinder block axis but allow the tilting.

To the upper edge of plate 26E in suitable ears is hinged a -link 36 the other end of which is hinged to a rod 36A `slidable in the .guide 36B and extending to and threaded in an adjusting -lenob 37 which-is shown best in Fig. 5 andis provided with arelatively long stern or shaft portion 37th-having an axial passage threaded at its inner endl to receive the rod 36A and 'enlarged inl its outer portion to provide for fixing to the rod end "a washer 37B acting as means to limit thelongitudinal movement of the rod, and thereby the angle of tilting of `the swash plate. j l

Surrounding rod 36A between guide 36B and the Yquill 28 and piston 30.

inner end of knob 37 is a suitable spring 136 under sufficient compression to hold the plate 26E in adjusted position against a predetermined back pressure, the knob being prevented from outward displacement by means of a pin 137 acting in a rather wide groove 138 in the stem of the knob. In order to provide for adjustment of spring 136, the end toward the guide 36B preferably carried on one of the rods serving as guides for the t plate 33.

In operation of the unit with a tool carried by the vquill 28, the stop 32C is set to properly limit Vthe tool feed,

and the knob 37 rotated to position plate 26E to determine the rate of feed. With the other parts in the positions shown in Fig. l, power is appliedto shaft 25. This starts the pump body 26 rotating and consequently iiuid delivery into the space between body 26 and piston 30.

However, with the valve 40 in the position shown, the fluid pressure on the piston cannot build up since the iiuid passes back through the passage 26A, 25B, 25C

Aand out into the casing.

In order to start the drilling or other operation, the

valve (not shown) admitting air to the right hand end of cylinder 34 through orifice 34A is then opened and at the same time, solenoid 42 is energized to close valve 49. The air cylinder 34 will then move the quill and cylinder 32 toward the left until one of the stops 5l shuts off the air pressure, and since in such movement the piston 3% is moving away from the pump body, oil iiows into the space through passages 27B, 30D and past valve 30E.

As soon as this quick approach is stopped with valve 40 closed, the iiuid pressure from the pump builds up and causes the feed of the quill and this may continue until the stop nut 32C strikes the shoulder 32D. However, it is preferred to so coordinate the air Valves and lsolenoid 42 that air pressure is admitted to the left end of cylinder 34 through the orifice 34B during the hydraulic feed as a safety measure and when the feed has carried the quill to the completion of its work, the solenoid is deenergized and thereby the valve 4t) opened so as to allow the air cylinder to retract the quill and cylinder 32, the fluid in the head of cylinder 27 flowing out through passage 26A.

The admission of air under pressure to the left end of cylinder 34 is an important feature of the construction and operation of the present machine in that by this means the danger of a break-through is prevented.

With the quill 28, piston 30, and the largertube 32 being moved longitudinally out of the casing by the .pressure created from pump 26, nut 32C will come against the stop shoulder 32D thereby stopping tube 32'), With piston stopped and pump 26 still pumping, excessive back pressure on the pump pistons will tend to increase the angularity of theswash plate 26E and thereby compress spring 136 and pull the knob 37 inwardly. The movement inwardlyof knob 37 will allow the electric switchv plunger 37E to drop in the groove 37D and thereby break all of the electric circuits,

v allowing Valve to be opened by spring 40C. If for any reason, excessive pressure should` build up in the pressure chamber in cylinder Z7, the safety valve 26M will permit escape of fluid. V .Y

I claim: v t y l. A hydraulic drill unit comprising a casing adapted Vto be filled with oil, a drive shaft extending into the casting and having fixed to its inner end a cylindn'calvcylinder block having a plurality of pump cylinders and pistons therein, a longitudinally arranged drive cylinder iixed to said block and having atv its free end an internally splined drive nut, a splined quill coacting with said nut and driven thereby, a piston mounted on said quill and slidably iitting said drive cylinder, and means for actuating said pump pistons whereby to deliver oil from said casing to said drive cylinder above said piston and thereby move said quill longitudinally in `said nut.

2. In a hydraulic drill unit in which a tool carrying quill is mounted for longitudinal movement, a coaxial drive shaft for said quill and hydraulic means for moving said quill, a pump for suppliug fluid under pressure to said hydraulic means, said pump including a coaxial cylindrical cylinder block xed to said drive shaft and having a plurality of substantially axially arranged pump cylinders therein, pistons in said cylinders, a swash plate for actuating said pistons in said cylinders and means for resiliently holding said plate in adjusted angular position.

ervoir, a lluid pump, and a longitudinally movable quill coaxially arranged and connected in driving relation,

Vmeans for moving said quill by means of fluid under pressure from said pump, said pump comprising a rotatable cylinder' block provided with substantially axially arranged cylinders each having a piston projecting from an end of the block, an angularly arranged plate contacting the ends of said cylinders, and resilient means for adjust- Ving and maintaining the angular position of said plate v a piston projecting from an end of the block, an angularly arranged plate contacting the ends of said cylinders, and resilient means for adjusting and maintaining the angular position of said plate, said plate under excessive back pressure in said pump being arranged to move to a position of greater angularity and thereby overcome the resilience of said adjusting and maintaining means, means for relieving the fluid pressure in said quill moving means consisting of a passage openingto said reservoir, a valve for said passage and means actuable by said plate to open said valve under said excessive pressure.

5. Ina hydraulic drill unit, a Idrive shaft, a fluid pump coaxial therewith and driven thereby, an hydraulic cylintending into said cylinder and driven thereby, a second cylinder enclosing the first cylinder and extending therebeyond, said quill being rotatably mounted in the extended portion in fixed .longitudinal relation thereto, hydraulic means aetuable by iiuid from said pump for mo\ ing said quill longitudinally and thereby said second cylinder, and means carried by the latter for limiting such movement.

6. In a hydraulic `drill unit a drive shaft, a iiuid pump coaxialtherewith and driven thereby, a coaxial hydraulic cylinder fixed to said pump and into which Vsaid pump is adapted to deliver uid under pressure, an axial passage leading through said pump from said cylinder, a second axial passage in said drive shaft forming a continuation of the first passage, an outlet passage leading from said Ving a longitudinally movable quill having at one end a piston, a cylinder coacting with said piston, pumping 3. In a hydraulic drill unit, a drive shaft, a fluid resj means for introducing fluid under pressure to the cylinder to move the piston, a drive shaft for actuating the pumping means and simultaneously rotating said quill, said drive shaft, pumping means and quill being arranged in coaxial relation, a cylinder parallel to said coaxis and having a piston connected to said quill and means =for supplying compressed air to said cylinder to resist the movement of said quill by the first mentioned cylinder and piston.

8. In a hydraulic drill unit, a `drive shaft, a fluid pump coaxial therewith and driven thereby, an hydraulic cylinder coaxial with and rotatable by said pump, a quill extending into said cylinder and driven thereby, a second cylinder enclosing the rst cylinder and extending therebeyond, said quill being rotatably mounted in the extended portion in fixed longitudinal relation thereto, hydraulic means actuable by fluid from said pump for moving said quill longitudinally and thereby said second cylinder, and means carried by the latter for limiting such movement, said limiting means comprising a fixed abutment and coacting stop means carried by said second cylinder.

9. In a hydraulic drill unit, a drive shaft, a fluid pump coaxial therewith and driven thereby, an hydraulic cylinf, der coaxial with and rotatable by said pump, a quill extending into said cylinder and driven thereby, a second cylinder enclosing the first cylinder and extending therebeyond, said quill being rotatably mounted in the extended portion in xed longitudinal relation thereto, hy-

draulic means actuable by fluid from said pump for movinlg said quill longitudinally and thereby said second cylinder, and means carried by the latter for limiting such movement, said limiting means comprising a fixed abutment, a stop nut mounted upon said second cylinder, and means for adjusting the position of said nut longitudinally of said second cylinder.

l0. In a hydraulic drill unit a drive shaft, a fluid pump coaxial therewith -and driven thereby, a coaxial hydraulic cylinder fixed to said pump and into which said pump is adapted to deliver fluid under pressure, an axial passage leading through said pump from said cylinder, a secondl axial passage in said drive shaft forming a continuation, of `the first passage, a radial outlet passage leading from said second passage, a valve adpted to open and close said outlet passage, said valve comprising a sleeve slidable upon said shaft.

References Cited in the tile of this patent UNITED STATES PATENTS 1,812,587 Ellis a- June 30, 1931 1,925,378 Ferris et al. Sept. 5, 1933 2,374,909 Williams May 1, 1945 2,374,764 Mathys May 1, 1945 2,554,381 Patterson May 22, 1951 2,631,431 Grebe et al. Mar. 17, 1953 2,643,555 Stei'bel lune 30, 1953 

